Britney Spears and Simon Cowell on The Ellen DeGeneres Show

X Factor judges Britney Spears and Simon Cowell make an exclusive appearance on The Ellen DeGeneres Show on Tuesday (September 11).

Britney opens up about being nervous on becoming a judge on the X Factor. Plus, Simon gives his thoughts on The Voice and who may be the new host of the X Factor.

Don’t miss when Ellen surprises Britney with Korean pop star PSY who teaches them how to dance Gangnam Style.

CLICK HERE to check out all of the clips from Britney’s interview!

Britney on being a judge on the “X Factor”:Ellen: “There is the saying yes and there is the reality of sitting there on the first day and realizing oh, I have to judge these people.” Britney: “Yeah.” Ellen: “Did you have doubts?” Britney: “I was really nervous. You have all these people behind you and you know they’re routing you on. Its really exciting, electric thing to do. But you know after we got out there and the cast is amazing. Demi and L.A. are great. And we had fun. We had a lot of fun.” Ellen: “Did you find it hard initially to be critical of people?” Simon: “No.” Britney: “That’s not true.” Simon: “Excuse me. I’ve never heard someone say no so quickly in my entire life.” Britney: “That’s not true. I used constructive criticism. I learned from the best…” (Pointing to Simon)Ellen: “He’s not constructive.” Britney: “He’s a little harsh. He can be a little harsh.” Simon: “That was my excuse for five years.” Britney: “I prefer to be honest. I think that’s the best way to go. I wouldn’t want to be told something and then waste seven years of my life. I feel like it’s the thing to do.” Simon: “I’m not disagreeing with you. I’ve been doing it for years.” Simon on “The Voice”:Ellen: “Ok, let’s talk about ‘The Voice.’ You’ve been very vocal that you’re not happy because you’re doing a two-night premiere, right?” Simon: “Yeah.” Ellen: “Two nights in a row.” Simon: “Yes, Wednesday, Thursday.” Ellen: “They (‘The Voice’) have now added another night to go up against your premiere. Is that right?” Simon: “Yeah, well literally about a week ago. We had the schedule set for months. They were going to go Monday, Tuesday. We were going to go Wednesday, Thursday. And, then they waited to the last second to announce that they were going to book a third show up against our premiere because they wanted to spoil our premiere.” (Audience boos)Ellen: “Would you ever do something like that?” Simon: “Never.” Ellen: “Don’t you think it’s a compliment because they are trying to compete with you? It’s a show…you kind of look at that as they are being competitive.” Simon: “I do to a point Ellen but I think when you play with the audience and you start messing around saying, now you can’t watch both shows. And, it is a spoiling tactic. I think what happened was…I know what happened is, they got wind of how good our first episode is. Britney, I have to say is amazing, as is Demi. And they have done this because they don’t want people to see them on the show. My gut feeling is that it is going to backfire on them because you don’t mess with the audience.” Simon on who is going to know be the new host:Ellen: “So who’s going to be the new host?” Simon: “We have screen tested a load of people.” Ellen: “But who’s going to be the host?” Simon: “I know whom I would like but now I have to get it approved by the network.